Selective removal of nitrate ions from water or aq. solns. - by ion exchange using succession of columns with weakly acidic cation exchanger then weakly basic anion exchanger before entering column filled with buffer

摘要

The removal of nitrate ions from water or aq. solns. is achieved by passing the liq. through a succession of exchange columns, whereby column (I) is filled with a weakly acidic cation exchanger, column (II) is filled with a nitrate-selective, weakly basic anion exchanger and column (III) is filled with a buffer. (I) contains an H(+)-type cation exchanger and (III) contains either a Na(+)- and/or Ca(2+)-type weakly acidic cation exchanger or a weakly basic OH(-) or CaCO3-type anion exchanger, whereby if (III) contains a weakly acid cation exchanger, the positions of (I) and (III) are interchangeable, depending on the nature of the packing of the respective columns. A sprinkler is pref. placed between (I) and (II). ADVANTAGE - The process allows for a selective removal of nitrate ions from both neutral and acidic media with enhanced efficiency.